Manifold



July 26, 1927. 1,636,721]

I J. w. SWAN MANIFQLD Filed Sept. 17. 1921 4.Sheets-Sheet 1 J. W. SWAN July 26, 1927.

MANIFOLD Filed Sept. 17. 1921 4 Sheets-Sheet z illl---i---i.i !-illl pn lli lhv illll Tl July 26, 1927.

J. W. SWAN MANIFOLD Filed Sept. 17, 1921 4 Sheets-Sheet 5 I & I

July 26, 1927.

J. W. SWAN MANIFOLD Filed Sept. 17. 1921 4 Sheets-Shae? 4 Patented. July 26, 1927.

PATENT OFFICE;

JOHN W. SWANQOF STAMFORD,ICONNECTIGUT.

umnrom).

Application filed September 17, 1921. Serial No. 501,814.

My invention relates broadly to fuel supplying means for internal combustion. engines and the like, which use gasolene, kerosene, and other light liquid fuels, and more particularly to the intake manifold thereof; and has for its primary object the provision of means which will enable the mixture of fuel and air to reach the cylinders of the engine in a uniform character throughout all of these cylinders, and in keeping with the intended adjustable control as to mixture at the carbureter. (The term uni-form character is intended to mean, not only, that the proportion of air to fuel in the mixture is the same reaching. all cylinders but, that the condition of such mixture as to the proportion of fuel in vapor and liquid form is the same, also that the quantity as well as quality of, the mixture reaching each cylinder is the same.)

Heretofore, much attention has been given to improved features of the carbureter per se, especially in air and ga'solene adjustments, it having been thought that if the carbureter could be adjusted to provide a predetermined or so-called perfect mixture, said mixture would pass from the carbureter to the cylinders without substantial-impairmentior'change. However, much difiiculty has been encountered in securing a charge to all cylinders in a uniform or even manner as to the quality and quantity or character of 'the mixture, it having been ascertained that notwithstanding the best adjustment possible b the carbureter, much, if not most, of t e gasolene will not vaporize in its passage from the carbureter to the respective cylinders, and by reason of the indifferent lack of consideration heretofore given the intake manifold, the latter, as

found in the art, causes an unequal distribu- Y tion of the liquid or gasolene to the several cylinders. The intake manifold as customarily provided presents a main uptake leading to a horizontal disposed supply pipe curving into lateral branches in turn coupled to the .engine casing and re storing with the intake openings of the various 0 linder's'. The construction of the supply plpe and branches forms an interior,ioftentimes irregular, at times presenting shoulders, depressions, or pockets, andmost usually with curved walls leading to the various branches, the branches occupying planes disaligned with the plane of the main su l i In these formations, it has been d igc v r d that the liquid or gasolene will cling to the walls of the manifold tending to feed ina direction contrary to the direction of supply to the cylinders, accumulating in places, and tending to follow a straight-line flow. This leads. to accumulations, even if only temporary, at points within the manifold-and tenuing to relatively enrich a part of the mixture leading to some of the cylinders vwhile correspondingly impoverishing the mixture leading to other cylinders.

Briefly, intake manifolds have been constructed as if the mixturedeaving the carbureter, was a gas and contained no liquid,

more attention being attached to. maintaining the same length of path 'orvchannel of flow to the various cylinders or groups of cylinders than to character of the path or channel. a I

With the foregoing in mind, I will now proceed to show that iny improvements may 7 be said to comprise a manifold which will not destroy the intended uniform character of the mixture as adjusted by the carbureter, but will permit the mixture in its predetermined character reaching all of the cylinders in substantially the same condition. that is,

uniformly as to proportions of fuel and air.

My manifold does this because it is so constructed as to make it'equally certain for the mixture to reach each cylinder in its turn, the character of the path of flow being the same from the carburetor to each cylinder and there being entire absence of pockets or depressions in the floor of the manifold. Moreover the manifold is so constructed as togive maximum turbulence where the mixture changes its direction of fiow, which further assists in maintaining. a uniform character of mixture;

The essential characteristics of my manifold arez'First, to make it e ually certain for the mixture to reach all cy inders in the same relative proportions as delivered by the carbureter, tlns being done by preventing the accumulation of liquid and anytendency for the mixture, particularly any liquid in the mixture, to have preference for certain cylinders; second, to cause a certain amount of turbulence in the mixture as it flows to the c linders, this being done in substantially t e same manner for each cylinder.

its axis and not opposite any branch outlet.

The last two essential elements of construc- 7 tion give exactly the same number of abrupt bends in the path of-flow from the carbureter to cylinders similarly located.

From the foregoing it may be seen that the character of the path of flow from the carbureter to each cylinder is substantially the same and there is no obstruction, depression or pocket in the main pipe or its branches. This characteristic construction insures even distribution of the mixture to all cylinders. The flat bottom causes any liquid to spread out and assists in its entering the mixture stream by evaporation. The

Iii

abrupt bends cause rebounding or spattering of any particles of liquid back into the mixture stream, this actlon may be calledturbulence, This turbulence assists in maintaining a uniformcharacter of mixture throughout the cross-section of flow to a cylinders.

It will be noted that in the construction described the mixture is never required to ump any gap to reach any cylinder. This prevents any separation of particles of liquld from the mixture stream going to that cylinder. It will also be noted that the mixture in turning to any cylinder must always make an abrupt bend, preferably at a right angle. This prevents any tendency for the particles of liquid in the mixture to carry by and have a preference to flow to certain cylnders. This turbulence assists in maintainmg a uniform character of mixture throughout the cross-section of flow to. all cylinders. Practical tests with my manifold have demonstrated that the "remarkable results attamed in a manifold of this character cannot be over estimated. Such uniform distribution, as this manifold gives, secures a smooth and easy running of the motor independently of the manipulating of the carbureter whether suddenly or gradually, prevents so-called choking of the-engine and will enable the engine to .run on the level, in high gear, at a speed so slow as to be diflicult to registerin the standard speedometers all of which tends to greatly increase economy.

In the drawings: Figure 1 is a side elevation; F1gure2 is a top plan;

Figure 3 is a transverse vertical section thru the main supply. pipe and the adjacent branch of the manifold;

Figure 4 is a top plan view with a horizontal section through one of the end branches of the manifold;

Figure 5 is an end view;

F igure 6 is a fragmental inner side view;

Figure 7 is a cross sectional view on the line 7-7 of the improved intake manifold;

Figure 8 is a horizontal section through a slightly modified form of manifold;

Figure 9 is a fragmental side elevation showing a slightly modified form of branch for the distributing chamber, and

Figures 10 and 11 are fragmental side elevations showing modified forms of the shape of the main distributing chamber.

In the drawings A indicates the engine casing and-B. the intake manifold for supplying the gasoline to the various cylinders of the engine. The manifold B comprises the longitudinally extendingsupply or distributing chamber 1, parallel with the engine casing, the end branch pipes 2, and the intermediate branch pipe 3, each of the branch pipes being provided on the end with a flange 4 adapted to engage the engine 0218- ing at the intake openings and to be secured thereover by bolts 5 and detachable heads or cross bars 6 adapted to bear against integral lugs 7 on the branch pipes 2 and 3. As more clearlyshown in Figures'ii, 5 and 7, thechamber 1 and branch pipes 2 and 3 are each substantially square in cross section, thereby providing a flat level, top and bottom surface over which the liquid will pass, as previously stated,

An intake pipe 7 of substantially square cross-section leads into the bottom of the chamber 1, midway between the ends and in line with but at a right angle to the intermediate branch pipe 3. This construction makes it necessary for the mixture to rise in the intake pipe 7 from the carbureter and impinge upon the top of the chamber 1 directly above the intake pipe 7 consecu-.'

tively as demanded by the cylinders as per their timing order; then to reach the branch pipe 3 and connecting cylinders or end branch pipes 2 and connecting cylinders the mixture must make an abrupt right angle turn. This impinging and abrupt right angle turn at this point causes turbulence, spat- I tering or rebounding and materally assists in maintaining the mixture in a uniform characterv throughout the crosssection of flow, more-over the tendency for the mixture to flow tothe various branch pipes and cylinders is exactly the same at thispoint.

After leaving the intake pipe 7 and flowing to any of the various branches it must travel through a channel having a plane or level bottom and of substantially rectangular cross-section either in the branches or in the main chamber 1. Any liquid droppin out of the mixture as at low velocity wi same.

readily flow along the bottom of the main chamber 1 and its branches. It should be particularly noted that the tendency to flow to either of the end branches is exactly the However, when the mixture leaves the main chamber 1 to enter either of the end branches 2 it again must impinge on a flat surface and make-an abrupt bend, the turn at these points (as shown) being abrupt right angles with substantially sharp corners. This abrupt rightangle turn and impinging again causes turbulence, rebounding or spattering and assists in maintaining the mixture in substantially the same uniform state as when it left the uptake pipe 7. This point of construction is very important as the end branches 2 must of necessity be at some little distance from the uptake pipe 7' and this extra turbulence is essential in order to maintain the same character of mixture for the end cylinders as for the middle cylinders. It should be particularly noted, in this connection, that the mixture does not leave the main chamber 1 without the impinging action on a flat surface and abrupt right angle turn, never leaving the mixture stream without this action; neither is it required to jump a gap either horizontal or vertical.

The ends of the body or main feed pipe of the intake manifold l are closed by detachable caps 19.

Branches 2 and 3 are preferably of truly square cross-section wit-h the bottom wall truly horizontal. but as will instantly appeal to persons skilled in the art, it isdesirable that my intake manifold as an attachment shall be applicable to motor vehicles now in use as well as to newidngines having similarly square intake ports, andto this end,

the end portions of the branches 2 and 3 may be graduallytapered ofi, see cross section, Figure 7, and in view Figure 6, to merge into a circular cnd opening to perfectly register with a corresponding circular opening to be in many engines now inuse.

in Figure 8 l have shown a manifold in.

which the area of the intake pipe 7 is greater than the area of the distributin chamber and to accommodate this enlarged intake the chamber 1 is provided, intermediate its ends, with the off set portion 20. In the case of a six cylinder engine while one cylinder fires at a time there is an overlapping in which the second cylinder commences to take a charge at the other side of the center before the first cylinder is filled, therefore the intake member must be approximately one and one-half times the area of the main distributing member.

While 1' have described the preferred form of the branches 2 and 3 as square in cross section I have found that-at times, where 'necessar for attachment to existing engines said ranches, may be round as I have illustrated in Figure 9, the main idea being to have the bottoms of said branches level throughout their length and on the same level as the bottom of the main distributing chamber 1, and of same shape in cross section and equal in area.

In Figures 10 and ll I have illustrated still further modifications which may be necessary in certain cases for adaption to existing engines, Figure 10 showing the front Wall 21 of the distributing chamber 1 at an angle and Figure 11 shows the top 22' of the distributing chamber rounded. However, in each of these constructions it will be noted that the bottom of the distributing chamber and the bottoms of the branches are on the same level throughout their length. Although the best results may not be had therefrom, a good distribution may be obtained where the distributing chamber has an irregular cross-sectional contour, or outline, deviating from the square or rectangular form, so long as the irregularity in contour is carried throughout 'the entire length of the distributing chamber, thus making it certain that the linear elements comprising the side and top surfaces of the distributing chamber shall be straight lines, (these linear elements being taken in the same direction as the axis of the distributing chamber) and also provided that the port openings to the branches are so placed that no portion ofan opening is below the flatlevel bottom of the distributing chamber.

Other essential points to notice are the entire absence of curves, pockets or dep1essidns. Should any liquid tend to travel along the side wall of the main chamber 1 the abrupt right angle turn at theends will break up this action. On the other hand, if the bend were a curve of appreciable radius the liquid would continue to flow along the side Wall into the branches and enrich the mixture reaching the extreme end cylinders. The fiat bottom presents a maximum of surface for evaporation of any liquid thereon,

thereby causlng a reater'quantity of air to come into contact withthe liquid and enables any unevaporated liquid to flow with equal ease to any cylinder, and prevents any tendency for the liquid to collect and be picked up later. Such construction prevents loading and uneven running of the motor particularly at low speeds.

At this point itis well'to state that a cross-sectional contour, or outline, involvmg a curve at the bottom does not give sat; is actory distribution because any liquid dropping out of the mixture tends to collect in a stream at the lowest portion of the bottom instead of spreading out. Once this liquid collects in a stream it is extremely difficult to again break it up and get it back into the mixture in divided form, moreover, when a curved bottom is used it is difficult to provide port openings to the branches without irregularities in the bottom surface and without having portions of such openings below portions of the bottom surface. These latter difficulties tend to make the liquid stream at" the bottom of the distributing chamber have preference for certain cylinders.

It will be noted that this manifold is so constructed as to not interfere in the least with any adjustment of the carbureter, and enables the engine to respond instantly to any changes in carburetor adjustment or throttle valve required by changing speed, load, road or atmospheric conditions. Such action cannot be obtained with a manifold having curved surfaces, uneven bottom, with pockets, depressions or recesses and gaps in the path of flow.

It will be clear that the invention is susceptible of adaption to an engine with any multiple of cylinders.

Ihave illustrated in the drawings, Figures 1 and 3, the assembling of my improved manifold with a carbureter 12 and an exhaustgas chamber 9 associated with the intake pipe 7'. However, these are not of the essence of the present invention and need not be set forth in detail or claimed in this application save to the extent of a reference to the fact that I am not in the use of my improved manifold, necessarily relying on the application of heating means to the intake pipe for the purpose of aiding distribution. I am cognizant of the diiiicultics encountered in any attempt to secure complete vaporization of a fuel or mixture before deliverance from the uptake of the branched portion of the manifold. Ordinarily this is impossible of accomplishment, and where it can be obtained, even under the most favorable conditions, it is only at the expense of other considerations such as the reduction of the so-called volumetric efhciency or ultimate power of the engine. The practice of my invention so far as even distribution of the fuel is concerned, does not depend on the degree of vaporization in the intake pipe. WVhere an exhaust gas or otherheating medium is employed in connection withmy intake pipe, such as 7' (that is, prior to delivcry to the branched portion of the manifold), it is my intention that the function thereof need be utilized only to the extent of supplying a temperature sufficient to prevent condensation of the moisture carried by the incoming mixture andwhich might-in instances tend to retard the speed of movement of the fuel from the carburetor through the intake to the branched manifold.

Having thus described my invention, what I claim isi 1. A manifold comprising a horizontally of the fuel, and the wall of the body of the manifold opposite the supply inlet thereinto being coincident with continuations of said wall which constitute the upper Wall of adjacent oppositely extending leads of the body portion from the distributing zone.

2. A manifold comprising a horizontally disposed body portion, a supply pipe adapted to discharge into the bottom of said body portion, the juncture between the supply pipe and the body portion being at thev distributing zone of the manifold and devoid of curved corners in the lines of travel of the fuel in the various directions, three outlet branches offset from the body portion of the manifold adapted to lead to cylinders, junctures between branches and the body portion at the inner side of any turn being devoid of any curvature in the line of travel manifold opposite the supply inlet thereinto being coincident with continuations of said wall which constitute the upper Wall of adjacent ppo'sitely extending leads of the body portion from the distributin zone whereby to favor neither one of sai leads as compared to the other, said Wall also being arranged with reference to the top wall of the third branch to further secure uniform distribution.

3. A manifold comprising a horizontally disposedbody portion, a supply pipe adapted to discharge into the bottom of said body portion, the juncture between the supply pipe and the body portion being at the distributing zone, and'devoid of curved corners in the lines of travel of the fuel in the varibetween branches and. the body portion at the inner side of any turn being devoid of any curvature in the line of'trav'el of the fuel, all of the outlet branches being in communication with the common distributing zone, and being cylindrical at, their terminal portions at least for registation with engine ports, the-uppler walls of the leads to the out ermost branc es immediately adjacent to the distributing zone being in substantially the Ill same plane as the wall of the distributing zone opposite the supply inlet, and the upper wall of the intermediate branchbeing so related to the said top wall of the distributing zone as to secure uniform distribution.

4. A manifold ,for gasoline engines comprising a main supply pipe having a lateral inlet and outlet branches at an angle to the inlet, the walls of the manifold being devoid of curved surfaces in the intended line of travel of the mixture through the manifold.

5. In amanifold for a six-cylinder internal combustion engine, the combination with a main manifold duct, level throughout its length, a straight or substantially straight riser duct connecting the carburetor with the central part of the main duct and being at right angles, or substantially at right angles thereto, the interior or the connection ofthe riser to the main duct being at a substantially uniformly sharp angle all around the connection, three secondary ducts each for connecting the main duct to two of the engine cylinders, the middle secondary duct being connected to the main duct at the junction of the riser with the main duct and at right angles, or substantially right angles thereto, a distributing zone with a nonrecessed roof being formed at the junction of the main duct, the riser and the middle secondary duct, the two other secondary ducts being connected to the main duct at the ends thereof, all of said secondary ducts being parallel, or substantially parallel to each other and perpendicular or substantially perpendicular to the main duct, on the interior the end secondary ducts making a right angle connection with the main duct at the sides nearest the middle and the middle secondary duct making a sharp connection with the interior of the main duct and all of said ducts and riser being curves and recesses in the direction of flow of the fuel mixture.

6. In a manifold,.the combination with a main horizontally disposed manifold duct, a straight or substantially straight riser duct atthe central part of the main duct and being at right angles, or substantially at right angles thereto, the interior of the connection of the riser to the main duct being at a substantially uniformly sharp angle all around the connection, three secondary ducts, the middle secondary duct being connected to the main duct at the junction of the riser with the main duct and. at right'angles, or substantially right angles thereto, a distributing zone being formed at the junction of the main duct, the riser and the middle secondary duct, the two other secondary ducts being connected to the main duct at the ends thereof, all of said secondary ducts bein parallel, or substantially parallel to eac other and perpendicular or substantially perpendicular to the main duct, on the interior dGVOld' of v the end secondary ducts making a right angle connection with the main duct at the-sides nearest the middle and the middle secondaty duct making a sharp connection with the interior of the main duct,

7. In a manifold for a six-cylinder internal combustion engine, the combination with a main manifold duct, level throughout its length, a straight or substantially straight riser duct connecting the carburetor with the central part of the main duct and being at right angles, or substantially at right angles thereto, the interior of the connection of the riser to the main duct being at a substantially uniformly sharp angle all around the connection, three secondary. ducts each for connecting the main duct to two ofthe engine cylinders, the middle duct with the two middle cylinders and each end duct to the two nearest end cylinders, the middle secondary duct being connected to the main duct at the junction of the riser with the main duct and at right angles, or substantially right angles thereto, a distributing zone with a roof having a curved portion being formed at the junction of the main duct, the riser and the middle secondary duct, the two other secondary ducts being connected to the main duct at the ends thereof, all of said secondary ducts bein parallel, or substantially parallel to each, other and perpendicular or substantially perpendicular to the main duct on the interior, each of the end secondary ducts making a right angle connection with the main duct at the sides nearest the middle duct and the middle secondary duct making a sharp connection with the interior of the main duct, and all of said ducts and riser being devoid of curves and recesses in the direction of flow of the fuel mixture.

8. In a: manifold for a six-cylinder in- .ternal. combustion engine, the combination with a main manifold duct, level throughout its length, a straight or substantially straight riser duct connecting the carburetor with the central part of the main duct and being at right angles, or substantially at right angles thereto, the interior of the connection of the riser to the main duct being at a substantiat ly uniformly sharp a'ngle all around the connection, three' secondary ducts, each for connecting the main duct to two of the engine cylinders, the middle duct with the two middle cylinders and each end duct to the two nearest end cylinders, the middle secondary duct being connected to the main duct at the junction of the riser with the main duct, and at right an Ice, or substantially right angles thereto, a 'stributing zone with a roof curved, on a eater radius than the adjacent secondary not and formed at the junction of the main duct, the riser and the middle secondary duct, the two other secondary ducts being connected to the main duct at the ends thereof, all of said secondary duct-s being parallel, or substantially parallel to each other and perpendicular or sub-' stantially perpendicular to the main duct on the interior, each of the end secondary ducts making a right angle connection with the main duct at the side nearest the middle duct and the middle secondary duct making a sharp connection with the interior of the main duct, and all of said ducts and riser being devoid of curves and recesses in the direction of flow of the fuel mixture.

' In testimony whereof I hereunto aflix my signature.

JOHN W. SWAN. 

